Why?

This is my first time blogging and am very eager to get started. I have found that the general people around me in my city, neighborhood and area have increasingly declined in social skills! For example last night I was in a Major Dept Store in our area exchaning an item. Simple task, should only take a few minutes. Well as I stand there at the sign that says "please form line here" I notice a young couple of mixed races standing over to the side but at the same distance from the counters as I. the cashier walks up, obviously sees me standing there but asks who is next in line...Well in a perfect world it should have been me. If this inter racial couple had any manners they would have said "oh she was standing here first" but alas they did not and went right in front of me. I tried to contain my unbelief that this had just happened but made a small comment to two young men standing behind them that "I must be invisible today". Now you would generally think that ok now I have to go to the end of the line cause obviously no one can read a sign anymore and have formed a line on the other side of counter. So as I turn to go to the end, the two young white men say" please go in front of us, you were obviously here first"! So my question of today is Why? Why do some people, not all, but the majority of people think it is there priviledge to step in front of other people in store lines? Are they any better than me? I'm not saying I'm any better then them. I just want to play fairly, be honest, have manners. the two younger men behind me had the manners and allowed me to go in front of them. Why didn't the inter racial couple feel they were allowed to go in front of me? Upbrining? Social Status? Lack of Manners? Why?